ST MARY’S CATHEDRAL, SYDNEY, 25 MARCH 2026
Every now and then, a single sentence captures an historical moment. We think: “That’s one small step for man, one giant leap for mankind.” “I have a dream.” “We shall fight on the beaches.” But the sentence or two that truly changed everything—dividing all time into before and after—was not spoken from the moon, a monument, or parliament, but in a small room, in an obscure town, two thousand years ago. “You will conceive the Son of the Most High God” said one; “Fiat: let it be done” said the other (Lk 1:26-38).
Cur deus homo? Christians of every generation have asked, “Why did God become man?” Great theologians and pastors from the New Testament onwards gave a similar answer, “God became human in order to save us.” He had tried various things: the natural law written on our hearts; the revealed law of Moses; the provocations of the prophets; constant efforts to woo back the Chosen People when they strayed. When all else had failed, God did the unthinkable—He sent His Son.
¸In his great work Cur deus homo? (1094–98) St Anselm of Canterbury argued that we owe God a great debt for our existence, our gifts, and our sinful misuse of both. Only a human being could justly pay the debt. But only God would be sufficient payment. So we needed a God-man to atone for us.
St Thomas, some generations later, agreed.[1] By offering Himself as man, God enabled man to make just satisfaction for our many failures. So God took upon Himself our sins and due punishment.[2] But, Aquinas observes, it didn’t have to be that way.[3] A simple divine thought, or act of will, or spoken word, and our debt would have been wiped clean.
¸So we’re back to our question: why the Incarnation? Well, St Thomas thought, it is of the essence of goodness—and wisdom, and justice, and might—to communicate itself, and so the God who is goodness itself fittingly communicates Himself in the most perfect way.[4] If we got a message saying “You’re saved” by SMS, or via some go-between, or even in cosmic skywriting, would we understand it, believe it, take it to heart? The best way to get a message across is directly, person to person.
What is more, Aquinas said, there’s something ‘fitting’ about God uniting Himself to a human nature in order to renew our human nature. By this clearest revelation of His truth, He engages our trusting faith in His Word. By this greatest demonstration of His promises, He stirs in us a certain hope. By this fullest outpouring of His love, He evokes our love in return. By this most benevolent of acts, He calls us to good deeds.
Thomas followed Augustine, who followed Athanasius, who followed Ireneus, in saying that “God became man so man might become God.”[5] With a little more precision than his predecessors, he says that by uniting Himself to a human nature, Christ enables us to be united to the divine. By becoming one of us, He dignifies us and deters the Evil One. By so dignifying and protecting us, He helps us not to sin. And by so humbly diminishing Himself, He enables us to demonstrate similar virtue. In these ways Christ prepares us for adoption into His divine family.[6]
¸That’s about ten Thomist reasons for the Incarnation for you to think about today—there are plenty more. But I think Thomas’ big reason is especially persuasive: if we were told that the Creator of the universe loves us to bits, if we saw skywriting that said He forgives us no matter what we do if we return to Him, if we got a text message that we could be united to God forever, we wouldn’t believe it. It sounds too good to be true. So God became one of us, that we might see and hear and touch Him as He walked among us, so He might give Himself completely for us on the Cross, the altar, our tongues. What Isaiah foretold was at last fulfilled: the virgin conceived and bore a son, God-with-us (Isa 7:14; 8:10).
¸My friends, it really happened this day. The angel Gabriel was sent to tell a young woman “You will conceive the Son of the Most High God” and to receive her consent “Fiat: let it be done”. At that moment the Creator became creature, the divine Word human flesh, and God sung you personally His love song Jesus.
[1] STh, IIIa, q. 1, a. 2.
[2] cf. Mt 1:21; 26:28; Rom 3:21–26; 5:8; Col 2:14; 1 Pet 2:24.
[3] STh IIIa, q. 1, a. 1.
[4] STh IIIa, q. 1, aa. 1-2.
[5] For the principle that God became human so that humanity might be divinised has a long pedigree. See Irenaeus, Adversus Haereses V, praef.; Athanasius, De Incarnatione 54.3; Augustine, Sermo 128.1. Thomas cites Augustine’s Sermo 13 de Temp. at STh IIIa, q. 1, a. 2.
[6] STh IIIa, q. 1, a. 2
INTRODUCTION TO MASS FOR THE SOLEMNITY OF THE ANNUNCIATION OF THE LORD
ST MARY’S CATHEDRAL, SYDNEY, 25 MARCH 2026
Welcome friends to St Mary’s Cathedral for our lunchtime celebration of the Solemnity of the Annunciation of the Lord. The Bishops of the Province of Sydney, the Archbishop of Canberra-Goulburn, and the eparchs of the other Catholic rites headquartered in this city, are presently meeting here at St Mary’s, and I welcome them concelebrating with me on this great feast. Though Holy Week is just around the corner, when we will ask “Why did He have to die?”, the Feast of the Annunciation provokes in us the prior question “Why did He have to be born?” As we contemplate this, we repent of our failures to respond in thought, word and deed to God’s great profession of love, the Incarnation…
